Tank. Definitely a tank. It has all the potential to let his bot mode still heavily resemble his G1 version (grey in color, arm canon, etc.) and also does away with all the mass shifting nonsense. G1 Megatron, while clever back in the day, is nonetheless a ridiculous and poorly thought out idea.

 

While I like the P-38 gun mode of G1 Megatron, I think that tank is the most efficient and appropriate alternate mode. Now when you say tank, many think a slow, thundering, powerful machine. Today tanks are fast with max speeds of 60mph, can turn on a dime and can flatten a whole neighborhood.

Just watch this vids:

And in the end I think G2 Hero Megs/Rebirth Megatron and Armada Megatron have the best alt modes.

 

A purple Tyrannosaurus Rex.
With a fake British Accent. ohh yesss.....

 

The jet mode from Energon is my favorite.

 

a tank without a dout

 

I'm torn. I was gonna say tank too outright but ZeroMayhem gives such a good argument, imo...

That, plus the decepticon army already has tanks innit. Megatron's alt mode should be something unique to him to signify his status as the leader.

Now, Shockwave did also transform into a gun, but he still flied around...and he transformed into a ginormous gun to boot...

 

I like Purple T-Rex for Megatron that made him more Meateaters than a Red Dragon.

 

Tank. It seems so much more fitting for his personality.

 

I'll go with the reasoning the movie had for him turning into a Cybertronian jet...

 

Rollerblading, jet-powered T-rex. Failing that, a jet or tank.

 

1) Tank. It just works for the big cannon, mobility, destructiveness.

2) Alien plane/jet. Fits him as a decepticon that he can fly. And he's arrogant enough not to need a disguise.

3) Stationary cannon of some kind - he doesn't need to move, he just blows stuff up where he is.

4) In a beast/animal world, a dragon or t-rex works.

 

If Megatron wasn't supposed to be a gun, then he should be the most badass guncarrying machine EVER aka A-10 Thunderbolt II

^^ his new fusion-cannon.

 

Megatron should be anytype of large gun, laser or otherwise. My second choice would be a a type of tank.

 

Never really warmed to the gun mode. I mean ever. Even when I owned him as a kid. I recognize the gun for it's now-classic associations, but I was there before it was classic, and I wasn't crazy about it then either.  

I never liked mass-shifting very much, and there's something about a gun that just seems small, and not proactive enough. A gun is a tool, in that it implies a need for a human user. I know that arguably all vehicles are tools, but there's really no denying that cars (etc) have a stronger sense of agency, perhaps due to the motor, or just the way we tend to anthropomorphize them. A mere slug-firing handgun just seems rather meek compared to even the throaty growl of a hot-rod engine, let alone a semi truck or a jet engine.

ANYWAY, I generally go with tank, because it seems the closest in spirit to his gun-mode. It's just a very LARGE gun, with more autonomy and mobility. When Megatron became a tank in G2, that was one of the few things I really liked about G2 (though green didn't suit him).

Alien gunship also seems reasonable, and gives Megs the ability to fly like most of his troops. Helicopters are sort of the tanks of the future, but I'm not sold on the helicopter... yet. TFA Megs might help me re-assess that.  

smog

 

A tank or some type of plane/jet/whatever.

...Although, a freaking flamethrower or one of more mean looking guns might not be that bad.  

 

A stationary object (like a gun or a cannon) has that element of "I am your leader! I'm not going to walk or fly anywhere, that's what you underlings are for!"-thing with them, really.  

If he has to be mobile in alt mode, it has to be something big with immense firepower and mass to throw around...like a tank.

 

I'll take the tank from armada even though I'm a g1 nut I don't like the fact he transforms into a gun and jets don't do it for me either

 

Hmm, it's pretty tough. I've always loved the idea of Megatron being a gun like in G1 almost as equally as him being a tank like in G2/Armada. Both are great. I even like the idea of him being a big gunship, like his Super Link encarnation.

But... Dragon wins. His Dragon mode from the end of Beast Wars was just about the most perfect alt mode for a Megatron. He's a powerhouse, no doubt, but he's also sleek and fast. Very regal looking, too. Oh yesss, Dragon it is. 

 

I Agree!
Hand was his best alt mode ever.

it'd be awesome if R.I.D. Megatron could hold G1 megatron.
That'd be the ultimate death machine.

my second choice would be a Quetzalcoatlus, a Giganotosaurus, and an Elasmosaurus at the same time!

 

I vote Tank, though the Ospreyish-copter-thing coming up for Animated may change my mind.